Hollow compound-metal article.



J. F. MONNOT. HOLLOW COMPOUND METAL ARTICLE. APPLICATION FILED DEC. 26, 1905.

1,,63,574 Patented June 3, 1913.

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ATTORNEYS UNITED STATES PATENT on JOHN FERREOL HONNOT, OF NEW YORK, N. Y., ASSIG-NOR TO DUPLEX METALS GOIMPANY, OF NEW YORK, N. A CORPORATION OF NEW YORK.

HOLLOW COMPOUND-METAL ARTICLE.

Specification of Letters Patent.

Patented June 3, 1913.

Application filed December 2d, 1905. Serial No. 293,410.

appertams to make and use the same.

This invention relates hollow compound metal articles and consists in hollow compound metal articles, and more particularly in cartridge shells and like articles, composed of a base or body of a ferrous metal covered and protected by a filmlike layer of hard, planished, dense, impervious unlike or non-ferrous metal, weld-united thereto and relying thereupon for support; all as more fully hereinafter set forth and as claimed.

Modern smokeless powders generally comprise or consistof nitro products which though usually sufliciently stable per se, nevertheless ar apt to undergo progressive decomposition or alteration in the presence of relatively minute amounts of many impurities. Such an alteration takes place after a time in smokeless powders loaded in the ordinary brass shells, the metal probably oxidizing and the oxids formed recip rocally influencing the nitro compounds, and

the charged cartridge becomes unreliable.

Itis therefore customary not to load such shells until immediately before probable use and to unload unused cartridges more than a few months old. Unloading and reloading are difficult, dangerous and expensive operations and the inconvenience of waiting for an emergency before beginning to load the number of cartridges required to supply an army is obvious. Furthermore in the operation of modern automatic fire-arms having delicate and complicated working parts it is necessary that a .shell shall be stiff and possessed of considerable mechanical strength to resist stresses and deformation while it-must also have a true surface and perfect shape to avoid jamming in the gun. The ordinary brass shell though expensive and, as stated, not free from a ,deteriorative action on nitro powders, in a measure complies with these requirements as regards I strength and surface, but its use is restricted to arms of comparatively small caliber since a prohibitive thickness of wall, both in point of cost and of Wei ht, would be required to glve a shell of su cient strength for large guns. Copper though substantially free from deteriorative act-ion on nitro powders has not suflicient mechanical strength for use in automatic rifles and machineguns. Steel is strong enough, but its surface, even when polished has too" great-a frictional coeflicient for practical use and of course it cannot bekept from rusting while it soon ruins powders.

It is the object of the present invention to provide a cartridge shell obviating the stated objections and attaining a number of new advantages. To this end, such" shells are made by a suitable treatment of compound metals resulting from a process for which I have received Letters Patent No. 851,684, April 30, 1907 ancLNo. 853,716, May

14, 1907, Briefly stated, the process therein described and claimed rests upon the fact which I have discovered that while steels and similar ferrous metals have no great aflinity for the chemically unlike non-ferrous ductile metals of high melting point, such as silver, copper and the various cupriferous alloys like brass and bronze, gold, aluminum, etc., and will not readily unite therewith to form good unions at the common casting temperatures, of such non-ferrous metals, yet

if the temperature at the abutting faces'of a body of steel and a body of such unlike, non-' ferrous metal be momentarily preserved at a point a number of hundred degrees above the meltlng point of such non-ferrous metal this lack of affinity disappears and good weld-likeyunions maybe readily secured, such unions resisting dissolution by changes of temperature or by mechanical stresses.

A copper clad steel billet so produced may be heated red hot and suddenly quenched without dissolution of the, union, and the coating cannot be split off by a cold chisel or like cutting tool, the tool refusing to follow the line-of union and diverging into the 10L softer metal. The coating may be of one metal, or of two, as when a steel billet is first filmed with a coating of copper applied in the described manner at the extremely high temperature used and then a coating of brass p or bronze applied to the filmed surface at ordinary casting temperature. Brass and bronze as containing low-melting, readily oxidizable metals like tin and zinc, donot readily withstand the application of temperatures much above their melting points and therefore in coating steel billets it is generally preferable to form such a preliminary film coating of a metal like copper which will tolerate the temperature necessary to produce What I have called the supermolten condition; a condition necessary to secure the union with steel. To this cop- 'pered surface, brass and bronze can be readily applied at ordinary casting temperatures, copper being like in nature to both alloys.

Clad steel billets produced in the described manner can" be as readily worked, and in the same manner as, simple steel billets. For such working it is of course necessary to employ as a coating metal a metal which, like those reviously enumerated, has a melting point above ordinary steel working temperatures; say above 900 F. or 500 C. I have discovered that by applying .a suitable thickness of one of these metals to a ferrous metal base in the described manner and then coextending the jointed metals to the thickness necessary for a cartridge shell by ordinarymetal working methods, I can produce a shell or other hollow article which while substantially all steel and possessing the stiffness, strength and resistance to deformation of steel, will nevertheless have a filmlike, wholly Qimpervious, dense and hard coating of the other metal, hermetically sealing in the surface to which it is applied and indissoluble therefrom by heat changes or mechanical forces. With a copper-clad shell of this character, the copper is altogether too thin to allow any substantial yielding to automatic loading and unloading mechanism in the. gun while at the samextime the underlying, highly frictional surface of the steel cannot contact with such mechanism or with the steel surface of the gun bore. In the coextension .of'the two metals, the copper is given a dense, compacted andplanishedsurface, extremely well adapted for smooth working in the gun, while, as stated, its thickness is wholly insufficient to permit any yielding to clutching mechanism or anyindentation which would mar the perfection of the surface. The copper is, as a matter of fact, of a tenuity so great that it must wholly rely for support on thesteel to which it is welded.

So far as the mechanical action in-the gun is concerned, brass-clad steel "shells work similarly to the/copper-clad, but they are not-so well adapted for containing nitro powders when the brass coating is interior as well as exterior. Copper is found in practice to exert very little action on nitro gitudinal section.

powders and it is therefore better adapted for the interior coating. Other cupriferous alloys than brass (zinc-copper) may however be used for interior coatings; such as bronze, aluminum bronze, and the like.

In producing shells and similar hollow articles under the present invention, I customarily employ from 3 to 5 per cent. of the coating metal in making the original clad billets and the same proportions between the joined metals will be found to exist after coextension and wo-rkin to form the shells, such joinedmetals wor one metal. Less or greater proportions of the coating metal may be employed but those indicated are satisfactory in practice.

To avoid exposure of the underlying'ferrous met-a1 in cutting large sheets to make,

blanks for shells and in cutting necessary orifices in such shells or hollow articles, I resort to an artifice. I have found that in cutting and punching if tools have a rounded or obtunding edge in lieu of the customary sharp edge, the softer coating metal will yield and flow to some extent before the severance of the stiffer steel and will cover the edges of the latter metal, sealing it in.

In the accompanying illustration, Figure 1 shows a .central longitudinal section of such cartridge shell. Fig. 2 illustrates the formation of the cap hole in the head of such shell, and the drawing of the coating metal over the edges formed by punching the cap hole, the figure showing the end-of the shell in section, and showing the male die in elevation and the female die in lon- Fig. 3 illustrates the compacting of the coating metal at the cap hole, showing the shell in section, together with its support, and showing the spinning or crimping tool in elevation. Fig. 4. shows an end view of a machine for cutting the ends of cartridge shells and similar tubular objects, and for drawing the coating metal over the cut edges; and Fig. 5'is a detail sectional view showing, greatly exaggerated, the theoretical form and' relative position, of the edges of the cutters. Fig. 6 is a detail perspective elevation and crosssection of a grooved spinning disk for uniting layers of coating metals over cut edges, in perfecting the union and covering effected by the stated obtunding tools.

In the said drawings, 1 deslgnates the core or base metal and 2, 2, the layers of coating metal. These layers are notnecessarily of the same coating metal; a cartridge shell, for example, may be coated on the inside with one metal, preferably copper or a resistant copper alloy for shells tobe used with nitro powders, and on the outside with another metal. I have not attempted to indicate any particular form or construction of cartridge .shell, except the constructiong like i that the coatings may be so drawn together merely by using a somewhat dull cutting or punching tool or tools, followed, if necessary, by rubbing, spinning or otherwise working together the meeting portions of the two coatings until the same are substantially united and a joint impervious to moisture and to oxygen and other chemicallyactive gases and vapors is formed. Figs. 2 and 3 illustrate how such a-joint may be formed at a punched hole, and Fig. 4 illustrates how such a joint may be formed at a cutedge. Referring first to Fig. 2, it will be seen that'the punch 4 of the male die 5 is somewhat blunt or dull, and is tapered, and thatthe female die 6 has-a bore 7 for the reception of this punch 4:, and has surrounding this' bore an annular outwardlytaper-ing edge 8. I find that in practice two such dies not merely punch out a clean hole in the end of the shell, but draw-the coating metal over the edge of the core, as illustrated with some exaggeration, in Fig. 2, so that the coatings meet, or substantially .so. For many purposes, it is suflicient to leave the punched hole in this condition; but if greater finish and a better joint is desired, the edge may be finished by means such as illustrated in- Fig. 3, comprising a hollow support 9 for the shell and a taper smooth ing-tool 10, either said shell or said tool 10 being revolved, the one with respect to the other, while the tool'presses against the edge of-the hole; the effect of such action being to compactthe coating metal by spinning or equivalent action; it being possible to so unite the two coating layers in this way that they become substantially one. A I

For cutting the shell to length and covering over the cut edge I may employ means such as illustrated in Fig. 4, comprising somewhat dull rotary cutters 11, 11, mount-' ed on shafts 12, 12, and arranged to be rotated by suitable gearing, as shown, the upper cutter, with its shaft and bearings, being adjustable up and down by means of a screw 13 or equivalent means. To support the shell while it is being cut, I may provideone of the shafts 12 with an extension having an adjustable mandrel 14 on which the shell fits snugly. Fig. 5 shows considerably enlarged and exaggerated, the

' form of the two cutters 11, the same having approximately V-shaped peripheries, the

extreme edges of which are blunt and-rounded as shown. After a shell has been cut oil by these rotary cutters, the substantially abutting portions of the two coating layers may be compacted and substantially united by a suitable spinning tool, which may for example be a grooved disk, such as is shown in Fig. 6.

I have not illustrated the dies for drawing the cartridge shell from the sheet to final form, but it will be understood that dies such as are ordinarily used for the purposemay be employed. But whereas in the drawing of brass cartridge shells, annealing and pickling are necessary after practically every step of the drawing, when using the compound metals above referred to only one or two annealings at the most are usually required. It will be seen, therefore,'that for this reason alone the cost of forming the cartridge shells is greatly reduced.

At present cartridge shells are usually formed of brass notwithstanding the serious objection that there is some slight chemical action by the brass on-many if not all of the explosives now commonly employed in cartridges, which results in gradual deterioration of cartridges, necessitating reloading at intervals. Copper is much superior to prising an iron or steel core and a coating .of copper, has even greater strength than brass, while having all of the properties of copper desirable in cartridge shells.

The steel core being covered by copper or the like metal, cannot give sparks in violent handling of the cartridges or in loading the same with steel tools, copper being a nonsparking metal. At the same time, the cartridge shell being substantially all steel, has the same rate of expansion and contraction substantially as a steel shell and it does not jam or stick in the gun or in ejector mechanism when such gun or mechanism, both of which are customarily made' of steel, becomes heated in firing, in the way iniwhich an all-brass or all-copper shell is apt toigs good, such coatings bemg' merely adherent to the base, and not coherent thereto, and

for this reason and also because of lack of cohesion in the coating itself, it is impracticable to roll or draw electro-plated metals without destroying the continuity of the coating. But the coatings of the compound metals, such as produced, for example, by the processes described in my Patents Nos. 851,684, dated April 30, 1907, and 853,716, dated May 14, 1907, are absolutely coherent to the base, are dense, hard and absolutely impervious to gases and liquids, and remain impervious, even when drawn to extreme thinness. A cartridge shell formed of such metal is therefore a materially different article from a shell coated by electro-plating, dipping or similar processes. In a steelcopper shell, the article mechanically is substantially steel, but the steel is hermetically sealed in by a surface-giving, impervious film of copper.

It will be noted that in the die 6 of Fig. 2, there is a slight annular depression at 15 between the cutting edge 8 and the outsideof the die. This depression isto allow space for the flow of the metal.

I do not in this application claim the method of drawing the coating metal over edges of compound metal objects nor the specific apparatus for performing the cutting, as while these are of my invention, they are covered by another application filed March 2, 1906, Serial No. 303,916.

By the term compound metal as herein used I do not intend to restrict myself to material coated on both sides with the same coating metal. Obviously the coating on one side may be of one material and that on the opposite side may be of another material, and the term compound metal as herein employed, is used as a generic term to designate material comprising a base of one metal and a coating or coatings therefor of one or more metals welded to saidbase.

What I claim is 1. As an article of manufacture, a hollow metal object having a wall composed of a thickness of compound metal comprising a ferrous metal body and an impervious, planished film-like coating of an unlike, highmelting nonferrous metal weld-united thereto, said coating being drawn over and covering the edges of the ferrous metal body.

2. As an article of manufacture, a hollow metal object having a wall composed 'of a thickness of compound metal comprising a ferrous metal body and an impervious, planished film-like coating of a cupriferous metal weld-united thereto, said coating. being drawn over and covering the edges of the ferrous metal body.

3. As an article of manufacture, a hollow metal object having a wall-composed of a thickness of compound metal comprising a ferrous metal body and an impervious, planished film-like coating of copper weld-united thereto, said coating being drawn over and coio iering the edges of' the ferrous metal bo y.

4. As an article of manufacture, a cartridge shell composed of a compound metal having a body of ferrous metal provided with an impervious, planished film like coating of an unlike, high-melting non-ferrous metal weld-united thereto, said coating being drawn over and covering the edges of the ferrous metal body.

5. As an article of manufacture, acartridge shell composed of a compound metal having a body of ferrous metal provided with an impervious, planished film-like coating of a cupriferous metal weld-united thereto, said coating being drawn over and covering the edges of the ferrous metal body.

6. As an article of manufacture, a cartridge shell composed of a compound metal having a body of ferrous metal provided with an impervious, planished film-like coating of copper weld-united thereto, said coating being drawn over and covering the edges of the ferrous metal body.

7. As an article of manufacture, a cartridge shell composed of a compound met-a1 having a body of ferrous metal provided with an impervious, planished, film-like coating of a high-melting unlike-non-ferrous metal weld-united thereto, said shell having a cap hole and having the coating metal drawn over and covering the edges of the ferrous metal at said cap hole and at the end of the shell.

8. As an article of manufacture, a cartridge shell composed of a compound metal having a body of ferrous metal provided with a film-like, impervious, planished coating of a cupriferous metal weld-united thereto, said shell having a cap hole and hav ng the coating metal drawn over and covering the edges of the ferrous metal at sald-cap hole and. at the-end of the shell. 

